Drill grinding attachment



NOV- 26, 1946 R. G. zENlCk V DRILL GRINDIN-G; ATTAG'HMENT Filed Jan. 19, 1945 IN VEN TOR. f?. CS. ZEN/CK Patented Nov. 26, 1946 '.UNITED STATES PATENT oEFlcE Raymond G. Zeniclr, Burbank, Calif. Application January 19, 1943, Serial No. 472,806

My invention relates to a drill-grinding attachment for grinding machines.

' One of the principal objects of this invention is to provide a grinding-attachment for use in connection Ywith the conventional grinder, and oneA whichi'is particularly simple and economical of construction, easy to apply or install on the grinder, and one which i-s easy to operate.

Another important'object of this invention is toprovide an attachment of this class which is constructed so that it may be easily applied or attached and also eiectively operated from or on either side of a revolving grinding wheel of the grinder'.

An important object also of this invention is to provide an attachment of this class which may be readily adjusted to accommodate drills of various lengths.

A further important object of this invention is to provide an 'attachment of this class whichIv may be readily adjustedtoward or from-the side faces of the revolving grinding wheel for decreasing or increasing, respectively, the clearance-of the" lips backwardly from the cutting edges of the drill.

Still another important object of this invention is to provide JKa Avery simple attachment of this class for easily and quickly adjusting the drill holder for varying the angles of the lips with respect to the axis of the drill, and to provide means in connection with the attachment for readily determining the desired angle.

With these and other objects in view as will appear hereinafter, I have devised a drill grinding attachment which will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanying drawing and to the characters of reference thereon, which form a part of this I application, in which:

Fig. 1 is a fragmentary front view of a conventional grinder showing my attachment mounted thereon, the attachment holding a conventional drill in position for grinding, dotted lines showing the attachment adjusted outwardly from the grinding wheel;

2 Claims. (Cl. 51-219) Fig. 4 is a fragmentary elevational view of the attachment, showing the pivotal portion from the side opposite to that shown in Fig. 1; and

Fig. 5 is a diagrammatic view of the side of the grinding wheel showing different positions of the lower lip during the process of grinding, said positions corresponding, respectively, to various positions or" the attachment when adjusted progressively outwardly' from the grinding wheel.

In the drawing, thegrinder or grindingy machine is designated I, and is shown as supported on a suitable table 2. The grinder has an emery wheel, or other suitable grinding member 3.

My drill grinding attachment is supported on the table 2 and is shown positioned at the outer side, which is the right side of the grinding Wheel'.

As shown in the drawing, my'attaohment is y supported on a pedestal II which has an elon-V Fig. 2 is a fragmentary top view of the grinding wheel showing the drill to be ground in its initial grinding position, and showing by dotted lines the same drill when rotated counter-clock- Wise with the drill holding portion of the attachment for grinding the clearance backwardly from the cutting edge.

Fig. 3 is a sectional view thereof, taken through 3-3 of Fig. 1;

gated base. consisting of two longitudinally slotted feet IIa. Through the slots of the feet extend anchor bolts I2. The anchor ybolts have wing nuts I3 for adjustably'securing the feet IIa on the table 2. The pedestal II has a vertical bore IIb into which extends a shank Illa. of

, the Vsupport 'I4 for swivelly supporting the support on the pedestal on a vertical axis. The drill holder I5 is provided at its underside and intermediate' its ends with a downwardly extending lug I53v which is swivelly mounted on a horizontal axis on a support I d, the latter swivel connection being provided by a bolt II which is also provided with an adjusting Wing nut I8. The drill holding portion of the member I5 is normally inclined at la substantial angle to the horizontal. This member I5 is provided at its upper portion With a longitudinal groove or channel I5b which i-s V-shaped, the angle of the V being substantially The downwardly extending lug I5a has, at the side opposite the upwardly extending lug Illb of the swivel or rotating support I4, a plate I6 on which is a dial. This dial has degree divisions or graduations adjacent the periphery. graduations radiate from the axis of the bolt I1. On the swivel or rotatable support I4 is an index mark I fic, which as shown in the drawing, may be seen through an arcuate slot in the dial member. There may also be provided an index mark I Ic on the side of the pedestal, which may be usedl The 3 head ilEL of the pivot bolt is also shown as engaging this flat side of the lug l'c. Thus, both the plate and the bolt are held against rotation.

Against the upper end of the drill holder, that is, the end normally adjacent the grinding wheel, is secured a drill guide i9, which is preferably made of tool steel, the same being shown best in Fig. 3. The drill D, to be sharpened and resting in the il-channel oi the drill holder, is adapted to rest upon said guide, the portion of the drill resting on the guide being the opposite edge portions of one of the ilutes of the drill.

From the other or lower end of the rdrill holder extends a long screw 2li, this screw being positioned below the V-groove or channel but parallel with the vertex thereof. On the screw are screwably mounted a stop washer 2l and a lock wing nut 22. The drill to be ground and positioned in the V-channel is limited at its lower end by resting against the stop washer or member 2l.

My drill grinding attachment is so constructed that the axis of the pedestal is adjusted a fixed position from the side face of the grinding wheel as indicated by A, this dimension being, for one form of my device, one and one-half inches. When so positioned, the end of the drill will extend approximately one-eighth of an inch beyond the upper end of the V-channel or beyond the tool steel guide orlip IS, with one of the cutting edges substantially vertical, as indicated by B in Fig. 5. When the grinding wheel is rotated and the drill is swung about the vertical axis of the pedestal, a clearance of approximately 12 will be provided on the lip of the drill. If the dimension A is increased to A', the lip clearance of the drill is slightly increased.

B, B', and B represent three positions of the lower lip of a drill in the process of grinding, and

correspond respectively to three positions of the pedestal moved progressively outwardly or away from the grinding wheel.

In the position of the drill holder, as shown by solid lines in Fig. l, the lip will be ground at about 59 with respect to the axis of the drill. By reason of the pivotal mounting of the drill holder about a horizontal axis of the swivel or rotating 4 support i4, this angle may be increased or decreased as desired.

Though I have shown and described a particular construction, combination, and arrangement of parts and portions, I do not wish to be limited to the same, but desire to include in the scope of my invention the construction, combination and arrangement substantially as set forth in the appended claims.

Iclaim: c Y

1. A drill grinding attachment for a grinding machine having a plane grinding surface, comprising a pedestal adapted to be mounted with respect to the grinding machine at a spaced distance from the grinding surface, a drill holder having a downwardly extending portion swivelly mounted on said pedestal, said drill holder having a drill positioning groove inclined upwardly toward the grinding surface, a stationary screw member secured to and extending from the lower end of the drill holder and positioned below and parallel to the groove therein, a drill stop screwably and rotatably mounted on the screw member, and a thumb nut on the screw member for fixing the position of the stop on the screw member.

2. A drill grinding attachment for a grinding machine having a plane grinding surface, comprising a pedestal adapted to be mounted with respect to the grinding machine at a spaced distance from the grinding surface, a support swivelly mounted on said pedestal and extending thereabcve, a drill holder having intermediate its ends a downwardly extending lug swivelly mounted on a horizontal axis on the upper portion of the support, said drill holder having a drill positioning groove for holding therein a drill adapted to extend at an angle toward the grinding surface, a dial plate on the lug, said plate having an edge engaging a flat portion on the lug, and a bolt swivelly supporting the drill holder on the support andsecuring the former in a pivotal position on the latter, the bolt also securing the plate to the lug, and the head of the bolt engaging said flat portion to hold the bolt against rotation.

RAYMOND G. ZENICK. 

